1125
Samsung joins Google in RCS shaming Apple
(www.theverge.com)
This is a most excellent place for technology news and articles.
The EU could have had an effect on it via the DMA, but it seems that not many people use iMessage in the EU. People use Whatsapp and Facebook Messenger way more here, so those are forced into opening up.
iMessage message bubble colors seem to be an US problem.